Controlling electric motors.



Patented Sept. 28, 1909.

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UNITED STATES PATENT OFFICE.

JOSEPH LOUIS ROUTIN, OF LYON, FRANCE.

CONTROLLING ELECTRIC MOTORS.

To all whom it may concern:

Be it known that I, JOSEPH LOUIS ROUTIN, residing at Lyon, France, haveinvented certain new and useful Improvements in G011- trolling ElectricMotors, of which the following is a specification.

The present invention has for its object a device which allows ofcontrolling an electric motor from a distance and of automaticallyinsuring its stoppage when the mechanism at the receiving station is ina certain position; it is particularly applicable to cases in whichgreat precision and high power are both required, for example forcontrolling the rotors of turbines in hydro electrical works or forcontrolling the movements of navigable vessels.

The annexed drawing represents a diagram of the entire arrangement at acontrolling station and ata receiving station.

Controlling statz'0n.The controlling station comprises an asynchronousmotor fed in single phase to the rotor 1 and carrying on the stator 2 athree-phase winding.

Receiving statz'0n.The receiving station comprises what I term athree-phase current receiver of orders and a continuous currentservo-motor.

The receiver of orders consists of an asynchronous motor the stator 4 ofwhich carries a three-phase winding connected to the stator 2 of thetransmitting station and the rotor 8 of which is fed in single phase bythe circuit which feeds the rotor 1 of the transmitting station.

The continuous current servomotor com prises in principle an auxiliarygenerator the armature 15 of which is in continuous rotation and thefield-magnet 18 of which is fed at variable tension by a potentiometer.It is this auxiliary generator which controls the armature 13 of thelocal motor, the fieldmagnet 14 of which is constantly excited.

The spindle 5 of the order-receiver acts by means of an endless screw ona worm wheel 6 fixed to a beveled pinion 7 the combined wheels 6 and 7are loosely mounted on a hollow shaft '7 concentric with the shaft 8which controls the rheostat of the auxiliary generator.

The wheel is geared to the planet-pinion 9, and a third beveled pinion10 fixed to the wheel 11, rigidly mounted on a hollow shaft 10concentric with shaft 8, completes the differential equipment whichallows of controlling the rheostat either by the order-re- Specificationof Letters Patent.

Application filed. February 10, 1908.

' gram). or the other by lowering one of the levers 16 v and 17 thisdisplacement effects the connec- Patented sept. 28, 1909. Serial No.415,159.

ceiver or by the shaft 12 of the local motor; the movement from 12 to 11is transmitted by means of worm gear.

To render the figures more clear all this first part of the apparatushas been shown in sectional plan view, whereas that which follows isshown in elevation.

The local motor comprises an armature 13 and field-magnet 14; the latteris constantly excited. At rest, the armature 13 is shortcircuited onitself (as shown in the dia- It can be started in one direction tion, inseries, of 13 and the armature 15 of the auxiliary generator.

The magnet coil 18 of the auxiliary generator is connected at one of itsends to one of the poles of the continuous current conductor w y, and atthe other to the small metal circle 19 which is fixed to thepotentiometer rheostat. On this circle bears continuously a movablecontact fixed to the arm 20, which is fixed to the shaft 8. On the sameshaft 8 are loosely mounted two other arms 21 and 22 which arecontinuously I pulled, by antagonistic springs, to turn in oppositedirections, and which at rest abut against stops 23 and 24. In additionto hav ing contacts 23 and 24, the arms 21 and 22 are provided with twomore contacts 23 and 24 connected respectively to the former, and whichrub against fixed contacts arranged in the circle 25. Between thesecontacts are arranged, as shown in the diagram, resistances r r r 1;etc., and connections c 0 0 etc. All the resistances r, r, r, 1:, etc.1",, are connected in series, and the whole is mounted as apotentiometer between the two conductors supplying continuous current at110 volts. At rest, the resistances r, and 1', are placed in shortcircuit by the abutment contacts 23 and 24 of the arms 21 and 22.

The displacement of the levers 16 and 17 is effected by theelectromagnets 26 and 27 respectively connected to the ends ofresistances r, and 1",. When is displaced toward the right it firstestablishes electric connection between 24*" and the fixed circle 19,and then, acting on a regulatable abutment screw, it moves 22 toward theright.

When 20 returns, 24 first abuts against 24, and then the connectionbetween 24 and 19 is broken; if 20 passes the position of rest andcontinues its movement toward the left it first establishes connectionbetween 23 and 19, and then 21 is itself moved with 20.

Act2'0n.-VVhen the rotor 1 is displaced at the controlling station therotor 23 at the receiving station is immediately displaced the sameamount and causes rotation of 5. Supposing that, by reason of thisrotation, the shaft 8 is rotated clockwise, when 2st moves away from 24the electro 26 attracts 16, and 15 sends a current into 13, whichproduces rotation of 12 in such direction that by the action of thedifferential the shaft 8 tends to be moved in anticlockwise direction.hen the displacement of 5 has ceased the arm 20 will thus be broughtback to the position of rest; 2%, abutting against 24-, will place 1',in short circuit, the electromagnet 26 will cease to attract the lever16; 13 will be placed in short circuit and consequently powerfullybraked, since 1% remains excited. If 20 moves to the left from theposition of rest, 23" is placed in connection with 19, and theshort-circuit to 1*, being broken the electromagnet 27 attracts, and 15sends into 13 a current tending to turn 12 in such direction that by theaction of the differential the shaft 8 tends to be rotated clockwise andto let 20 return toward the right,

Since the resistances r, r. r etc. are all connected in series and forma potentiometer, the excitation of 18 and consequently the speed of 13will become greater as 20 is moved from the position of rest. By theaction of the differential the speed of 13 tends always to becomeproportional to that of Any order comprising a sudden variation,important in the position of the conducting member, will be executed athigh speed, whereas the small displacements will be executed slowly.

If it is desired to insure synehronism for control of all the receiversin the service, it is sufficient to arrange matters so that thereceiving motor, at the maximum tension which can be supplied thereto,communicates to the movable member of the differential a speed exceedingthat which the latter re ceives from the three-phase order receiver.

l v hen it is desired to vary the execution of the order transmitted itis sufficient to open the interrupter 28; on the other hand, when it isdesired to procure the execution of the order registered by thedisplacement of 20, it is sufficient to close 28.

It may be desirable (for example, in the ease ofeontrolling theregulating devices of groups of electro-generators when a new unit isbrought into service) to be able to cause at will, at reduced speed, theexecution of the registered order; for this it is suffi. cientto operatethe reverser 29 before closing the interrupter 28, which producesinstantaneous execution.

It is always desirable to interpose between 12 and the controlled devicea non-reversible worm gear transmission.

If there is risk of shocks on stopping, by reason of the speed acquired,one may mount the screw between two series of Belleville disks, so as toenable it to make a certain axial movement.

If there is risk of reversibility of the mechanism, there is placed onthe shaft of the motor a brake which is electrically disengaged, eitherby the main current or by a special control.

in all cases where there is risk at the moment of stoppage, of apowerful electric b ake current, it is desirable to momentarily keep thelever 16 or 17 lowered until the current has dropped to a valueapproxhmiting to that which can be furnished by the hysteresis of theauxiliary generator. For this purpose two electromagnets traversed bythe main current are added to the reverser.

(,Yrnaictrf'ioms mi 10cc. If/zc con-trolling smzi'on. and ru'ciaiug9?l'(tZ"? ()')'I/.-Tl]t% lines of connection for the transmission oforder comprise five wires two of which are used for feeding insingle-phase the rotors of the receivers. and three for the connectionsbetween the stators.

hat I claim as my invention and desire to secure by Letters Patent ofthe llnited States is 2* 1. A servo-motor comprising in combination apolyphase current transmitter; a polyphase current receiver; anauxiliary geuerator the excitation of which is controlled by thereceiver: a motor with constant excitation fed by the auxiliarygenerator, :1 difii'erential gear whereby the motor reacts on theexcitation of the auxiliary generator and a reverser controlled byrelays, adapted to come into action when the auxiliary generator isexcited.

2. A servo-motor comprising in combination a polyphase currenttransmitter, a polyphase current receiver; an auxiliary generator theexcitation of which is controlled by the receiver; a motor with constantexcita tion fed bv the auxiliary generator, a differential gear wherebythe motor reacts on the excitation of the auxiliary generator and areverser controlled by relays, adapted to come into action when theauxiliary generator is excited and to automatically establish ashort-circuit at the terminals of the armature, when the motor is to bestopped.

In witness whereof I have signed this specification in the presence oftwo witnesses.

JOSEPH LOUIS ROUTTN.

\Vitnesses Tnos. N. Browne, MARIN VACHON.

